@import 'variables';

// A collection of mixins and CSS classes that can be used to apply elevation to a material
// element.
// See: https://www.google.com/design/spec/what-is-material/elevation-shadows.html
// Examples:
//
//
// .mat-foo {
//   @include $mat-elevation(2);
//
//   &:active {
//     @include $mat-elevation(8);
//   }
// }
//
// <div id="external-card" class="mat-elevation-z2"><p>Some content</p></div>
//
// For an explanation of the design behind how elevation is implemented, see the design doc at
// https://goo.gl/Kq0k9Z.

// Colors for umbra, penumbra, and ambient shadows. As described in the design doc, each elevation
// level is created using a set of 3 shadow values, one for umbra (the shadow representing the
// space completely obscured by an object relative to its light source), one for penumbra (the
// space partially obscured by an object), and one for ambient (the space which contains the object
// itself). For a further explanation of these terms and their meanings, see
// https://en.wikipedia.org/wiki/Umbra,_penumbra_and_antumbra.

$_umbra-color: rgba(black, 0.2);
$_penumbra-color: rgba(black, 0.14);
$_ambient-color: rgba(black, 0.12);

// Maps for the different shadow sets and their values within each z-space. These values were
// created by taking a few reference shadow sets created by Google's Designers and interpolating
// all of the values between them.

$_umbra-elevation-map: (
  0: '0px 0px 0px 0px #{$_umbra-color}',
  1: '0px 2px 1px -1px #{$_umbra-color}',
  2: '0px 3px 1px -2px #{$_umbra-color}',
  3: '0px 3px 3px -2px #{$_umbra-color}',
  4: '0px 2px 4px -1px #{$_umbra-color}',
  5: '0px 3px 5px -1px #{$_umbra-color}',
  6: '0px 3px 5px -1px #{$_umbra-color}',
  7: '0px 4px 5px -2px #{$_umbra-color}',
  8: '0px 5px 5px -3px #{$_umbra-color}',
  9: '0px 5px 6px -3px #{$_umbra-color}',
  10: '0px 6px 6px -3px #{$_umbra-color}',
  11: '0px 6px 7px -4px #{$_umbra-color}',
  12: '0px 7px 8px -4px #{$_umbra-color}',
  13: '0px 7px 8px -4px #{$_umbra-color}',
  14: '0px 7px 9px -4px #{$_umbra-color}',
  15: '0px 8px 9px -5px #{$_umbra-color}',
  16: '0px 8px 10px -5px #{$_umbra-color}',
  17: '0px 8px 11px -5px #{$_umbra-color}',
  18: '0px 9px 11px -5px #{$_umbra-color}',
  19: '0px 9px 12px -6px #{$_umbra-color}',
  20: '0px 10px 13px -6px #{$_umbra-color}',
  21: '0px 10px 13px -6px #{$_umbra-color}',
  22: '0px 10px 14px -6px #{$_umbra-color}',
  23: '0px 11px 14px -7px #{$_umbra-color}',
  24: '0px 11px 15px -7px #{$_umbra-color}',
);

$_penumbra-elevation-map: (
  0: '0px 0px 0px 0px #{$_penumbra-color}',
  1: '0px 1px 1px 0px #{$_penumbra-color}',
  2: '0px 2px 2px 0px #{$_penumbra-color}',
  3: '0px 3px 4px 0px #{$_penumbra-color}',
  4: '0px 4px 5px 0px #{$_penumbra-color}',
  5: '0px 5px 8px 0px #{$_penumbra-color}',
  6: '0px 6px 10px 0px #{$_penumbra-color}',
  7: '0px 7px 10px 1px #{$_penumbra-color}',
  8: '0px 8px 10px 1px #{$_penumbra-color}',
  9: '0px 9px 12px 1px #{$_penumbra-color}',
  10: '0px 10px 14px 1px #{$_penumbra-color}',
  11: '0px 11px 15px 1px #{$_penumbra-color}',
  12: '0px 12px 17px 2px #{$_penumbra-color}',
  13: '0px 13px 19px 2px #{$_penumbra-color}',
  14: '0px 14px 21px 2px #{$_penumbra-color}',
  15: '0px 15px 22px 2px #{$_penumbra-color}',
  16: '0px 16px 24px 2px #{$_penumbra-color}',
  17: '0px 17px 26px 2px #{$_penumbra-color}',
  18: '0px 18px 28px 2px #{$_penumbra-color}',
  19: '0px 19px 29px 2px #{$_penumbra-color}',
  20: '0px 20px 31px 3px #{$_penumbra-color}',
  21: '0px 21px 33px 3px #{$_penumbra-color}',
  22: '0px 22px 35px 3px #{$_penumbra-color}',
  23: '0px 23px 36px 3px #{$_penumbra-color}',
  24: '0px 24px 38px 3px #{$_penumbra-color}',
);

$_ambient-elevation-map: (
  0: '0px 0px 0px 0px #{$_ambient-color}',
  1: '0px 1px 3px 0px #{$_ambient-color}',
  2: '0px 1px 5px 0px #{$_ambient-color}',
  3: '0px 1px 8px 0px #{$_ambient-color}',
  4: '0px 1px 10px 0px #{$_ambient-color}',
  5: '0px 1px 14px 0px #{$_ambient-color}',
  6: '0px 1px 18px 0px #{$_ambient-color}',
  7: '0px 2px 16px 1px #{$_ambient-color}',
  8: '0px 3px 14px 2px #{$_ambient-color}',
  9: '0px 3px 16px 2px #{$_ambient-color}',
  10: '0px 4px 18px 3px #{$_ambient-color}',
  11: '0px 4px 20px 3px #{$_ambient-color}',
  12: '0px 5px 22px 4px #{$_ambient-color}',
  13: '0px 5px 24px 4px #{$_ambient-color}',
  14: '0px 5px 26px 4px #{$_ambient-color}',
  15: '0px 6px 28px 5px #{$_ambient-color}',
  16: '0px 6px 30px 5px #{$_ambient-color}',
  17: '0px 6px 32px 5px #{$_ambient-color}',
  18: '0px 7px 34px 6px #{$_ambient-color}',
  19: '0px 7px 36px 6px #{$_ambient-color}',
  20: '0px 8px 38px 7px #{$_ambient-color}',
  21: '0px 8px 40px 7px #{$_ambient-color}',
  22: '0px 8px 42px 7px #{$_ambient-color}',
  23: '0px 9px 44px 8px #{$_ambient-color}',
  24: '0px 9px 46px 8px #{$_ambient-color}',
);

// The css property used for elevation. In most cases this should not be changed. It is exposed
// as a variable for abstraction / easy use when needing to reference the property directly, for
// example in a will-change rule.
$mat-elevation-property: box-shadow !default;

// The default duration value for elevation transitions.
$mat-elevation-transition-duration: 280ms !default;

// The default easing value for elevation transitions.
$mat-elevation-transition-timing-function: $mat-fast-out-slow-in-timing-function;

// The default color for elevation shadows.
$mat-elevation-color: black !default;

// The default opacity scaling value for elevation shadows.
$mat-elevation-opacity: 1 !default;

// Applies the correct css rules to an element to give it the elevation specified by $zValue.
// The $zValue must be between 0 and 24.
@mixin mat-elevation(
  $zValue,
  $color: $mat-elevation-color,
  $opacity: $mat-elevation-opacity
) {
  @if type-of($zValue) != number or not unitless($zValue) {
    @error '$zValue must be a unitless number';
  }
  @if $zValue < 0 or $zValue > 24 {
    @error '$zValue must be between 0 and 24';
  }

  box-shadow: #{map-get(_get-umbra-map($color, $opacity), $zValue)},
    #{map-get(_get-penumbra-map($color, $opacity), $zValue)},
    #{map-get(_get-ambient-map($color, $opacity), $zValue)};
}

// Returns a string that can be used as the value for a transition property for elevation.
// Calling this function directly is useful in situations where a component needs to transition
// more than one property.
//
// .foo {
//   transition: mat-elevation-transition-property-value(), opacity 100ms ease;
//   will-change: $mat-elevation-property, opacity;
// }
@function mat-elevation-transition-property-value(
  $duration: $mat-elevation-transition-duration,
  $easing: $mat-elevation-transition-timing-function
) {
  @return #{$mat-elevation-property} #{$duration} #{$easing};
}

// Applies the correct css rules needed to have an element transition between elevations.
// This mixin should be applied to elements whose elevation values will change depending on their
// context (e.g. when active or disabled).
//
// NOTE(traviskaufman): Both this mixin and the above function use default parameters so they can
// be used in the same way by clients.
@mixin mat-elevation-transition(
  $duration: $mat-elevation-transition-duration,
  $easing: $mat-elevation-transition-timing-function
) {
  transition: mat-elevation-transition-property-value($duration, $easing);
  will-change: $mat-elevation-property;
}

// Colors for umbra, penumbra, and ambient shadows. As described in the design doc, each elevation
// level is created using a set of 3 shadow values, one for umbra (the shadow representing the
// space completely obscured by an object relative to its light source), one for penumbra (the
// space partially obscured by an object), and one for ambient (the space which contains the object
// itself). For a further explanation of these terms and their meanings, see
// https://en.wikipedia.org/wiki/Umbra,_penumbra_and_antumbra.

// Maps for the different shadow sets and their values within each z-space. These values were
// created by taking a few reference shadow sets created by Google's Designers and interpolating
// all of the values between them.

@function _get-umbra-map($color, $opacity) {
  @return (
    0: '0px 0px 0px 0px #{rgba($color, $opacity * 0.2)}',
    1: '0px 2px 1px -1px #{rgba($color, $opacity * 0.2)}',
    2: '0px 3px 1px -2px #{rgba($color, $opacity * 0.2)}',
    3: '0px 3px 3px -2px #{rgba($color, $opacity * 0.2)}',
    4: '0px 2px 4px -1px #{rgba($color, $opacity * 0.2)}',
    5: '0px 3px 5px -1px #{rgba($color, $opacity * 0.2)}',
    6: '0px 3px 5px -1px #{rgba($color, $opacity * 0.2)}',
    7: '0px 4px 5px -2px #{rgba($color, $opacity * 0.2)}',
    8: '0px 5px 5px -3px #{rgba($color, $opacity * 0.2)}',
    9: '0px 5px 6px -3px #{rgba($color, $opacity * 0.2)}',
    10: '0px 6px 6px -3px #{rgba($color, $opacity * 0.2)}',
    11: '0px 6px 7px -4px #{rgba($color, $opacity * 0.2)}',
    12: '0px 7px 8px -4px #{rgba($color, $opacity * 0.2)}',
    13: '0px 7px 8px -4px #{rgba($color, $opacity * 0.2)}',
    14: '0px 7px 9px -4px #{rgba($color, $opacity * 0.2)}',
    15: '0px 8px 9px -5px #{rgba($color, $opacity * 0.2)}',
    16: '0px 8px 10px -5px #{rgba($color, $opacity * 0.2)}',
    17: '0px 8px 11px -5px #{rgba($color, $opacity * 0.2)}',
    18: '0px 9px 11px -5px #{rgba($color, $opacity * 0.2)}',
    19: '0px 9px 12px -6px #{rgba($color, $opacity * 0.2)}',
    20: '0px 10px 13px -6px #{rgba($color, $opacity * 0.2)}',
    21: '0px 10px 13px -6px #{rgba($color, $opacity * 0.2)}',
    22: '0px 10px 14px -6px #{rgba($color, $opacity * 0.2)}',
    23: '0px 11px 14px -7px #{rgba($color, $opacity * 0.2)}',
    24: '0px 11px 15px -7px #{rgba($color, $opacity * 0.2)}'
  );
}

@function _get-penumbra-map($color, $opacity) {
  @return (
    0: '0px 0px 0px 0px #{rgba($color, $opacity * 0.14)}',
    1: '0px 1px 1px 0px #{rgba($color, $opacity * 0.14)}',
    2: '0px 2px 2px 0px #{rgba($color, $opacity * 0.14)}',
    3: '0px 3px 4px 0px #{rgba($color, $opacity * 0.14)}',
    4: '0px 4px 5px 0px #{rgba($color, $opacity * 0.14)}',
    5: '0px 5px 8px 0px #{rgba($color, $opacity * 0.14)}',
    6: '0px 6px 10px 0px #{rgba($color, $opacity * 0.14)}',
    7: '0px 7px 10px 1px #{rgba($color, $opacity * 0.14)}',
    8: '0px 8px 10px 1px #{rgba($color, $opacity * 0.14)}',
    9: '0px 9px 12px 1px #{rgba($color, $opacity * 0.14)}',
    10: '0px 10px 14px 1px #{rgba($color, $opacity * 0.14)}',
    11: '0px 11px 15px 1px #{rgba($color, $opacity * 0.14)}',
    12: '0px 12px 17px 2px #{rgba($color, $opacity * 0.14)}',
    13: '0px 13px 19px 2px #{rgba($color, $opacity * 0.14)}',
    14: '0px 14px 21px 2px #{rgba($color, $opacity * 0.14)}',
    15: '0px 15px 22px 2px #{rgba($color, $opacity * 0.14)}',
    16: '0px 16px 24px 2px #{rgba($color, $opacity * 0.14)}',
    17: '0px 17px 26px 2px #{rgba($color, $opacity * 0.14)}',
    18: '0px 18px 28px 2px #{rgba($color, $opacity * 0.14)}',
    19: '0px 19px 29px 2px #{rgba($color, $opacity * 0.14)}',
    20: '0px 20px 31px 3px #{rgba($color, $opacity * 0.14)}',
    21: '0px 21px 33px 3px #{rgba($color, $opacity * 0.14)}',
    22: '0px 22px 35px 3px #{rgba($color, $opacity * 0.14)}',
    23: '0px 23px 36px 3px #{rgba($color, $opacity * 0.14)}',
    24: '0px 24px 38px 3px #{rgba($color, $opacity * 0.14)}'
  );
}

@function _get-ambient-map($color, $opacity) {
  @return (
    0: '0px 0px 0px 0px #{rgba($color, $opacity * 0.12)}',
    1: '0px 1px 3px 0px #{rgba($color, $opacity * 0.12)}',
    2: '0px 1px 5px 0px #{rgba($color, $opacity * 0.12)}',
    3: '0px 1px 8px 0px #{rgba($color, $opacity * 0.12)}',
    4: '0px 1px 10px 0px #{rgba($color, $opacity * 0.12)}',
    5: '0px 1px 14px 0px #{rgba($color, $opacity * 0.12)}',
    6: '0px 1px 18px 0px #{rgba($color, $opacity * 0.12)}',
    7: '0px 2px 16px 1px #{rgba($color, $opacity * 0.12)}',
    8: '0px 3px 14px 2px #{rgba($color, $opacity * 0.12)}',
    9: '0px 3px 16px 2px #{rgba($color, $opacity * 0.12)}',
    10: '0px 4px 18px 3px #{rgba($color, $opacity * 0.12)}',
    11: '0px 4px 20px 3px #{rgba($color, $opacity * 0.12)}',
    12: '0px 5px 22px 4px #{rgba($color, $opacity * 0.12)}',
    13: '0px 5px 24px 4px #{rgba($color, $opacity * 0.12)}',
    14: '0px 5px 26px 4px #{rgba($color, $opacity * 0.12)}',
    15: '0px 6px 28px 5px #{rgba($color, $opacity * 0.12)}',
    16: '0px 6px 30px 5px #{rgba($color, $opacity * 0.12)}',
    17: '0px 6px 32px 5px #{rgba($color, $opacity * 0.12)}',
    18: '0px 7px 34px 6px #{rgba($color, $opacity * 0.12)}',
    19: '0px 7px 36px 6px #{rgba($color, $opacity * 0.12)}',
    20: '0px 8px 38px 7px #{rgba($color, $opacity * 0.12)}',
    21: '0px 8px 40px 7px #{rgba($color, $opacity * 0.12)}',
    22: '0px 8px 42px 7px #{rgba($color, $opacity * 0.12)}',
    23: '0px 9px 44px 8px #{rgba($color, $opacity * 0.12)}',
    24: '0px 9px 46px 8px #{rgba($color, $opacity * 0.12)}'
  );
}
